GNGTS 2024 - Atti del 42° Convegno Nazionale

Session 2.2 GNGTS 2024 Glass panels (1300x1900h mm) consist of insulated glass units (IGUs) where two laminated elements (4+4 mm thick annealed glass panels with two PVB interlayers) are spaced by a 16 mm cavity. Each panel is supported by two semng blocks made of aluminium alloy with a layer of plasCc material (rubber pad) on top, located at about L/10 from the end of the transom, where L is the length of the transom. Glass panels are then fixed in posiCon by means of pressure plates, which are screwed to the aluminium frame. The clearance between glass panels and frame is about 6 mm. Finite Element model A geometrically simplified and computaConally efficient numerical model - inspired by the strategic modelling steps discussed by Caterino et al. (2017) - was implemented in SAP2000 (Fig. 1(a)). The model consists of 1D beam elements to accurately represent the mechanical properCes of the aluminium frame mullions and transoms. The laber are assumed to be hinged at both ends. 2D shell elements are employed to describe the insulated glazing units (IGUs), with their total thickness corresponding to the sum of the glass layers (thus excluding cavity and PVB layers). A linear consCtuCve law is adopted for both glass and aluminium, with input material properCes summarized in Tab. 1. Two different link types available in SAP2000 are employed to reproduce the mechanical interacCons between the different components of the façade: ● "Gap" links are used to represent potenCal contact between IGUs and frame members following clearance closure. To account for the role of semng blocks, the gap value for the respecCve links is set to zero. ● "Wen" links are used to characterize the mechanical behaviour of the gaskets. The typical simulaCon consisted of nonlinear Direct-IntegraCon Cme-history analysis in displacement control. For the validaCon of the numerical model, the experimental displacement Cme-history was applied to the intermediate constrained joints, while the displacement obtained from a natural earthquake record (Newhall - Los Angeles County Fire StaCon) was used to evaluate the effecCveness of the isolaCon system (Fig. 1(b)). The chosen mesh size results in approximately 450 frame elements, 1200 shell elements, and 1600 joints.